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2 SheetsSheet 1.

(No Model.)

D. M. SWAIN.

STEAM BOILER FURNACE.

No. 310,153. Patented Dec. 30, 1884.

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A M fw -(No Model.) 2 Sheets-Sheet 2. D. M. SWAIN.

STEAM BOILER FURNACE.

I No. 310,153.

Patented Dec. 80, 1884.

W H i e ANMNNI a a e v 8 u% S. f bm UNITED STATES I PATENT OFFICE.

DAVID M. SYVAIN, OF STILLYVATER, MINNESOTA, ASSIGNOR, BY MESNE ASSIGNMENTS, OF ONE-HALF TO E. S..BRO\VN, RECEIVER OF THE NORTH- WESTERN MANUFACTURING AND OAR COMPANY, OF SAME PLACE.

STEAM-BOILER FURNACE.

SPECIFICATION forming part of Letters Patent No. 310,153, dated December 30, 1884.

Application filed August 19, 1881. (No model.)

To all whom, it may concern:

Be it known that 1, DAVID M. SWAIN, a citizen of the United States of America, residing at Stillwater, in the county of Washington and State of Minnesota, have invented certain new and useful Improvements in Steam-Boiler Furnaces; andI do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The object of the first part of my invent-ion is to prevent the light materials which are used for fuel from being lifted from the furnace-bars or the grate and forced against the ends of the fines and clogging them; and to this end it consists in combining with the furnace a series of movable fingers, bars, rods, or other equivalent devices arranged within the furnace and near its forward end, as will be hereinafter explained.

The second part of the invention consists in arranging a valve or damper in the flue or draft space at the front end of the boiler adapted to close such space when the engine is going uphill or downhill, for the purpose 0 of checking the draft, and thereby reducing the intensity of the combustion in order to prevent the burning out of the fines while they are uncovered at one end by reason of the inclined position of the boiler.

The third part of the invention consists in so attaching the ash-receptacle, and so shaping and arranging the parts to which it is attached that the receptacle shall be formed of the innerwall of the water-chamber of the .ro boiler, and shall be surrounded with water,

whereby the heat of the metal is reduced and the heat is utilized in the water.

Figure 1 is a side elevation of one of the boilers, parts of the shell being broken away.

5 Fig. 2 is an end view, partly in section. Fig. 3 is a vertical section on line x :0, Fig. 1. Fig. 4 is aview of the front end of the fire-box and ash-pan. Fig. 5 is avertical longitudinal section of the fire-box part of the boiler, a portion of the tubular part being shown in elevation. Fig. 6 is a detached view of rear vertical plate. Fig. 7 is a detached view of the front fine-plate. Fig. 8 is a detached view of the gusset or throat-plate, and Fig. 9 is a detached view of the thimble of the ash-hole.

A is the furnace, having a grate of the usual construction, bars being shown at a.

B is the horizontal part of the boiler con taining tubes or fines c, and carrying a steam dome, b.

O is the smoke-stack commnnicatingwith the smokechamber, arranged at the front end of the tubular part B to receive the products of combustion which pass through the fines c.

D is a damper hung in the smoke chambero 5 on shaft (1, which has its hearings in the walls of said chambm. As shown in the drawings, this damper is turned up into a vertical position above its shaft (1, thus permitting a free passage of the products of combustion through the fines 0; the smokechamber, and thence out through the smoke-stack 0; but when the engine is moving up or down an incline the damper may be swung down into the position indicated in dotted lines, Figs. 1 and 3, and thus made to substantially close the front ends of the upper rows of fines, so as to greatly reduce the draft and intensity of combustion within these flues, thereby preventing them from becoming unduly heated at their exposed end, as they would otherwise become when in an inclined position with their ends uncovered by water. Under some circun1- stances it is not desirable to entirely shut off the draft through any of the fines, but to S 5 graduate the shutting off or closing of the fines from the upper ones downward,it being never, under ordinary circumstances, necessary to shut off the draft through the lower ones at all; hence the damper D is hinged on a line 0 immediately above the fines, so as to swing outward and downward, and thus the closing .of the upper flues may be effected to any desired degree. As the damper is laid in one piece and hinged in the manner described, it 5 can be operated by a far simpler method than that which has been necessary with the shutoff mechanism heretofore used.

I am aware that with stationary boilers use has been made of a sliding damper arranged [O( to almost entirely shut off some of the fines without partially shutting off the draft through those below; and also aware that adjustable slat-like guides have been employed with 10- comotives to guide the currents to a central point, and I do not claim such constructions. It will be observed that this damper does not cover the ends of the lower row of fines, and that, therefore, sufficient draft is kept up to maintain combustion of the fuel within the furnace.

In Fig. 3 I have represented a weighted arm or counterpoise, E, secured to shaft d by set-screw e, and adapted to retain the damper D in the position shown in full lines, so that it will not be subject to casual displacement in any position which the boiler will assume under ordinary circumstances; but I do not wish to be limited to the use of such counterpoise or weighted arm, as I may employ some other contrivance for moving the damper or for retaining it in its upright position.

F is the aslrreceptacle. It is arranged below the furnace-grate, and is provided with an opening, f, at its forward end, through which the ashes and cinders may be discharged by means of aralie or hoe, G. This ash-recep tacle is formed within the body of the waterchamber of the boiler. The outer wall or shell. of the boiler or water-chamber has the opening f formed therein, said wall or shell extending entirely around said opening. The inner wall of the furnace is composed of sheet )I, which is bent into the form of a tube having a flat top, parallel straight sides, and curved bottom,the front flue-plate, L, Fig. 7, and rear vertical plate, N, Fig. 6. By an examination of these figures it will be seen that the plate N has its outer edge turned inwardly, ibrming a circumferential flange, n, the edge which surrounds the opening being turned outwardly to form a flange, n. The ilueplate L has its outer edge turned outwardly to form a llange, 1*. A portion of its lower end is also swaged into a flange, 7, to receive a thimble or tubular extension, 5, which is riveted thereto.

The throat-plate or gusset I, in addition to the usual flanges 1) f, is provided near its lower end with an outwardly projecting flange, 1), (see Figs. 5 and 8,) to which the outer end of the thimble or tube-section Z is riveted, thus forming an ash-hole, through which the ashes may be discharged from the ash-rcceptaclc below the grate-bars. The outer shell orjacket of the fire-box portion of the boiler extends entirely around the boiler, and is riveted at its rear edge to the inwardlyprojecting flange oz of plate N, and is at its front edge riveted to the shell of the boiler and to the flange p of the gusset P. lVithin the furnace are a series of vibrating rods or fingers, H, pivoted at their upper ends upon a transverse rod, h, which in turn is supported from the wall of the furnace by means of brackets or ears 1', one car being preferably employed at each end of the rod; or a grate or a perforated sheet of metal may be used in place of the independently-vibrating arms H,

said plate or grate being hinged by its upper edge at some convenient point to the inner wall of the fire-box. It will be readily seen from an inspection of the drawings that such fingers, grating, or plate will prevent light fuelsuch as strawfrom being carried by the draft against the rear open ends of the fines, and thereby prevent any undue checking of the draft, as I have found that without such device loose straw will sometimes be forced against the lines and close or partially close them, such closing reducing materially the effectiveness of the boiler. Some of the smaller and lighter pieces of the burning straw will almost necessarily pass the fingers and bars and accumulate more or less between said fingers and the boiler-sheet. By my construction such accumulation of refuse can be readily removed at any time by vibrating or moving the fingers, pulling them outward a little at the lower ends, the hinged connection at the upper ends permitting this movement.

I am aware that water-tubes have been rigidly and permanently attached in front of the ends of the fines, and also aware that station ary rods have been used at the inner or farther end of the fire-fluc in return-flue boilers, and I do not claim such constructions; but b situating the fingers at the furnace end of the boiler I prevent the straw from being carried inward by the strong blast, and by attaching them in the manner that I have shown upon a hinging rod they can be readily detached at any time, if such detaching is rendered necessary, either by the burning out of the fingers or inorder that the coal or other heavy fuel can be used instead of straw.

I am aware that it is old to surround the fire-boxes and ash-pans of steam-looilers by a water-jacket, and hence do not claim such a construction,broadly; butI believe a furnacechamber constructed of the parts which I have described possesses advantages which are not incident to any other construction of which I am aware.

\Vhat I claim is 1. In a boiler-furnacefor burning light fuel, the combination, with the fines c and the furnace, of a series of movable fingers or bars between the grate and the furnace end of the flues, substantially as set forth.

2. In a steam-boiler, the combination of the inner tubular sheet, M, the flue-plate L, provided with flanges Z F, the gusset or throatplate P, provided with flanges p p and the thimble Z, the rear flanged plate, N n a, and the outer shell or jacket, Q,whereby there is formed an ash-receptacle provided with a front opening for the discharge of ashes, the tubular wall of which, together with the bottom of the ash-pan, may be surrounded with water, substantially as set forth.

In testimony whereof I affiX my signature in presence of two witnesses.

Vitnesses: DAVID M. SWAIN.

H. J. CHAMBERS, W. S. GoonI-rUE.

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